package demo3;
class Student12{
    String name;
    int age;
    void read() {
        System.out.println("大家好，我是"+name+", 年龄"+age);
    }
}
public class d3 {
    public static void main(String[] args) {
        Student12 stu = new Student12();
        stu.name = "张三";
        stu.age = -18;
        stu.read();
    }
}